N-cyanoimines and n-cyanoaziridines

ABSTRACT

1. AN N-CYANOIMINE OF THE FORMULA   R1-C(-R2)(-R3)-C(-R)=N-CN   WHEREIN THE R&#39;&#39;S TAKEN INDIVIDUALLY, CONTAIN UP TO 18 CARBONS AND ARE MEMBERS OF THE GROUP CONSISTING OF HYDROGEN, ALKOXY AND HYDROCARBYL AND ANY TWO R&#39;&#39;S MAY BE JOINED TO FORM A DIVALENT ALKYLENE GROUP PF 2-10 CARBONS.

United States Patent O T N-CYANOIMINES AND N-CYANOAZIRIDINES Frank Dennis Marsh, Wilmington, Del., assignor to E. I.

du Pont de Nemours and Company, Wilmington, Del. No Drawing. Application July 16, 1964, Ser. No. 383,233,

now Patent No. 3,510,474, which is a continuation-inpart of abandoned application Ser. No. 234,878, Nov.

1, 1962. Divided and this application June 11, 1969,

Ser. No. 832,423

Int. Cl. C07c 119/00 U.S. Cl. 260453 R 8 Claims ABSTRACT OF THE DISCLOSURE Described and claimed are N-cyanoimines, which are hydrolyzable to the corresponding carbonyl compounds and cyanamide, and N-cyanoaziridines. Said N-cyanoimines are useful as adhesives for bonding neoprene as Well as intermediates for preparing cyanamide and carbonyl compounds. The compounds are obtained by reacting cyanogen azide with monomeric precursors containing the nonaromatic C=C bond.

RELATED APPLICATIONS This application is a division of my copending application Ser. No. 383,233, now US. Pat. 3,510,474, filed July 16, 1964, as a continuation-in-part of my copending application Ser. No. 234,878, filed Nov. 1, 1962, and now abandoned.

BACKGROUND OF THE INVENTION (1) Field of the Invention This invention relates to new kinds of nitrogen compounds, N-cyanoimines and N-cyanoaziridines.

(2) Description of the Prior Art Brigl, Berichte, vol. 45, p. 1557 (1912) purports to show an N-cyanoimine in formula II. He rejects it as not representing the compound he prepared from cyanamide and acetoacetic ester.

Goldberg and Golov, Reactions of Cyanamide and Ketones, Khim. Nauka i From, 4, 138 (1959); C.A., vol. 53, col. 16953 (1959) purport to show the preparation of N- cyanoimines by reaction of cyanamide with ketones. The reaction products have an indeterminate structure however and are not the compounds of this invention.

Warning: Cyanogen azide is explosive when free or nearly free of solvent and should then be handled with great care. It can be used, however, with comparative safety in dilute or moderately concentrated solution.

DESCRIPTION OF THE INVENTION The novel products of this invention are derived from ethylenically unsaturated precursors.

- The products obtained by reaction of cyanogen azide with ethylenically unsaturated compounds vary in complexity from comparatively simple compounds obtained by reaction of a single molecule of cyanogen azide with a molecule of a monomeric compound containing a single ethylenic linkage to polysubstituted products obtained by reaction of a number of cyanogen azide molecules with a monomeric molecule containing a plurality of ethylenic linkages. The basic reaction in all instances is the same, however, and results in the formation of products containing one or more of the characteristic groups.

wherein the dangling valences are attached either to two separate adjoining carbons of an organic group thereby forming an N-cyanoaziridine, i.e., a compound contain- 3,849,465 Patented Nov. 19,. 1974 ing an N-cyanoazacyclopropyl group, or to a single carbon of an organic group to form an N-cyanoimine. In the reaction of cyanogen azide with a monoethylenic compound, a mixture of N-cyanoaziridine and N-cyanoimine is generally formed, whereas in the addition of cyanogen azide to compounds containing two or more ethylenic groups, the products may contain both N-cyanoaziridin'e and N-cyanoimine groups in the same molecule. These reaction products, the preparation of which is described more fully in my copending application Ser. No. 383,233, are as follows:

(l) N-cyanoaziridines of the formula (as v I v wherein the Rs (R, R R and R3) individually are members of the group consisting of hydrogen, halogen, nitro, hydroxy, cyano, alkoxy, aryloxy, alkylsilyl, alkylthio, acyl, acyloxy, carboxyl, carbamoyl, N-hydrocarbylcarbamoyl, hydrocarbyloxycarbonyl, e.g., alkoxycarbonyl,hydrocarbyl, including alkyl, aryl, aralkyl, alkylaryl, cycloalkyl, and alkenyl, and substituted hydrocarbyl groups containing one or more of the previously mentioned groups as substituents, e.g., haloalkyl, haloaryl, hydroxyalkyl, hydroxyaryl, cyanoalkyl, cyanoaryl, alkoxyalkyl and alkoxyaryl, said Rs individually containing up to 18 carbons; and where any two R's may be joined together to form an alkylene or oxygen-interrupted alkylene group of up to 14 carbons. These compounds are obtained by the reaction of cyanogen azide with monomeric ethylenic compounds of the formula R(R )C= (R )R which preferably contains up to a total of 18 carbons; and

(2) N-cyanoimines of the formula RZ(IJCII=NCN R (II which are likewise obtained by reaction of cyanogen azide with monomeric ethylenic compounds of formula R(R )C=(R )R wherein the Rs' have the previously indicated meanings. A preferred group of N-cyanoalkyl ideneimines are those of the formula R =NCN p f 'IUII wherein R is cyclopentylidene or bicycloheptylidine, A wide variety of monomeric ethylenically unsaturated compounds can be reacted with cyanogen azide inpre: paring the N-cyanoaziridines and/or the N-cyanoimines; of this invention. The ethylenic compound can be-mono ethylenic or polyethylenic, cyclicor acyclic, and substiq, tuted or unsubstituted. When the vethylenic compoundcon tains one or more substituents, i.e., when it is not wholly hydrocarbon, suchsubstituent, if electron withdrawing, is

preferably at least one carbon removed from the ethyleni-- cally unsaturated carbon atoms. There is no preference or; restriction for the location of electronrdonating substitucuts as reactions proceed readily whatever the relativeposition of the substituent with respect totheethylenically,

unsaturated carbon. Some polymerization of thelethylenic. compound may occur as a side reacion, particularly in the case of readily polymerizable vinyl compounds.

Examples of simple monomeric monoethylenic compounds which can be used include ethylene, propylene, 3-

phenyl-l-propene, butene-l, butene-Z, isobutylene, hexenes, octenes, dodecenes, octa-decene's, 1,2-di rnetl 1ylcyclo.-.v

propene, butane,

cyclobutene, cyclopentene,

methylenecyclomethylcyclopentene,

methylenecyclo pentane,

methlenecyclohexane, cyclohexene, cycloheptene, .cyclo-; decene, cyclododecene, vinylcyclohexane, bicycloheptene,

styrene, p-ethylstyrene, fi-vinylnaphthalene, stilbene, and substituted monoethylenic compounds, such as allyl bromide, allyl alcohol, allyl acetate, allyl phenol, vinyl chloride, vinyl fluoride, vinylidene chloride, vinylidene fluoride, tetrafluoroethylene, vinyl methyl ketone, allyl phenyl ether, vinyl ethyl ether, vinyl phenyl ether, dihydrofuran, dihydropyran, vinyl ethyl sulfide, vinyl acetate, vinyl butyrate, nitroethylene, 3-nitro-1-propene, p-nitrostyrene, acrylonitrile, methacrylonitrile, 1,4-dicyanobutene-2, allyl cyanide, acrylic acid, crotonic acid, maleic acid, cinnamic acid, ethyl crotonate, butyl acrylate, benzyl acrylate methyl methacrylate, acrylamide, N-diethyl acrylamide, m-iodostyrene, p-cyanostyrene, o-hydroxystyrene, omethoxystyrene, and 2-({3,5-dicyano-a-hydroxyvinyl)-4- inethylphenol (US. 2,726,249).

Typical examples of dienes and other polyenes that can be used as the ethylenic reactant are butadiene, isoprene, chloroprene, 2,4-hexadiene, diallyl, cyclopentadiene, dicyclopentadiene, vinyl cyclohexene, di'vinyl ether, 1,5- cyclooctadiene, 1,3,5-hexatriene, and cyclooctatetraene.

v The preferred unsaturated reactants are substituted and unsubstituted ethylenic (i.e., olefinic) hydrocarbons of the formula R(R )C=O(R )(R particularly those of 2-12 carbons. Halogen, cyano, hydroxy, carboxyl, alkoxy, and alkoxy carbonyl are the preferred substituents for the substituted hydrocarbon reactants.

EMBODIMENTS OF THE INVENTION There follow some examples which are intended to illustrate, but not to limit, the invention. Examples 1-27 illustrate the reaction of cyanogen azide with ethylenically unsaturated compounds and the products obtained thereby. Some of these examples show isolation of the principal product only, whereas others, where both the N-cyanoaziridine and the N-cyanoimines are formed in substantial amounts, show the isolation of both products.

EXAMPLE 1 A 1 00-ml. flask equipped with a wet-ice condenser, magnetic stirrer, gas-inlet tube, and nitrogen bubbler was assembled, flame-dried and cooled to ambient temperature u nder nitrogen. Sodium azide (3.25 g., 0.05 mole, sieved through a 60 mesh screen) was added and the flask cooled in a solid carbon dioxide-acetone bath. Cyanogen chloride (28.8 g., 0.47 .mole) was condensed into the flask and allowed to warm to reflux temperature for 24 hours under nitrogen, Pure cyclohexene (20 ml., 16.2 g., 0.197 mole) waisthen added during /2 hour. The mixture was stirred at room temperature for hours and finally warmed slowly to 68. C. during 1 /2 hours. The resulting slurry of product and sodium chloride was cooled to room temperature, diluted with acetone ml., 15.8 g., 0.27 mole), and filtered. Removal of the solvent from the filtrate under reduced pressure gave 5.75 g. (yield 94%) of a lightlstraw-colored oil. Distillation of this oil in an acidwashed still gave 4.55 g. (74.5% yield) of pure l-N- cyanoiminocyclohexane (b.p. 26 C-/0.2[L; n 1.5025).

Analysis.-Calcd. for C' H N C, 68.81; H, 8.24; N, 22.93. Found: C, 69.01; H, 8.42; N, 23.35, 23.09.

Infrared analysis of this product showed strong absorption at 4.55 and 6.15 which is consistent with the structure of the. product.

1-N-cyanoiminocyclohexane obtained as above polymerized readily when heated and the polymer thus obtained is useful as a protective coating.

(principal product) Using essentially the procedure described in Example 1, sodium azide (19.5 g., 0.3 mole, sieved through a 60 mesh screen), cyanogen chloride (115 g., 1.87 mole), and bicyclo[2.2.1]hept-2-ene (50 g., 0.54 mole) were refluxed (ca. l618 C.) for about 20 hours, during which time nitrogen was liberated. The mixture was then heated to 55 C. to remove excess cyanogen chloride, cooled to ambient temperature, and then diluted with 50 cc. (39.6 g.) of dry acetone. The mixture Was filtered under nitrogen to separate sodium chloride and the solvent removed from the filtrate on a rotary evaporator at 0.3 mm./50 C. thereby leaving 5 g. of product mixture. This mixture consisted of approximately of the N-cyanoaziridine, 3-cyanoazatricyclo[3.2.1.0 ]octane, shown in formula A above, and 20% of the N-cyanoalkylideneimine, bicyclo [2.2.1]heptane-2-N-cyanoimine, formula B, below:

The components of the above mixture (5 g.) were separated and identified as follows: The mixture was passed over a column packed with 160 g. of a neutral hydrous alumina. The column was eluted with benzene, and the solvent was evaporated yielding a colorless, mobile liquid whose infrared spectrum was the same as that of the starting material, except for the following:

(a) The original band at 6.1a C=N) was absent. (b) A new band appeared at 5.75 C=O).

The new band was attributed to norcamphor from the hydrolysis of the bicyclo[2.2.1]heptan-2-N-cyanoimine (compound B). Distillation of the chromatographed mixture removed the volatile norcamphor which was isolated and identified as its 2,4-dinitrophenylhydrazone derivative, melting point 130 C. The 5.75 band was absent in the remaining liquid. The remainder of the spectrum was unchanged. This material was assigned the structure of compound A, 3-cyanoazatricyclo[3.2.l.0 ]octane.

The structure of the N-cyanoaziridine derivative was further verified by reduction with lithium aluminum hydride as follows:

To 300 ml. of dry diethyl ether in a 500-ml. flask, equipped with a magnetic stirrer and drying tube, 3 g. (0.08 mole) of lithium aluminum hydride was added. The mixture was stirred at room temperature for 24 hours, and there was then added 2.5 g. (0.02 mole) of the adduct of cyanogen azide with bicyclo[2.2.1]hept-2-ene in 35 ml. of diethyl ether over a period of 30 minutes. The reaction mixture was stirred for 26 hours at room temperature and was then decomposed with a saturated solution of sodium sulfate. The inorganic salts were removed by filtration and the filtrate evaporated to yield 2.3 g. of a mobile aminesmelling liquid. The nitrile band (4.5g) in the infrared spectrum was essentially absent.

To 900 mg. of the amine obtained as above in 7 ml. of cyclohexane there was added 2 g. (0.015 mole) of phenyl isothiocyanate. The exothermic reaction which ensued was cooled in an ice bath and the resultant solid triturated with 40 ml. of cyclohexane. It was then filtered to yield 1.3 g. of a product melting at l13 C. Re-

Analysis.-Calcd. for C H- SN c, 68.8; H, 6.6; N, 11.5; 8, 13.12. Found: 0, 68.86, 6886,11, 6.68, 6.72; N, 11.33, 11.39; s, 13.23, 13.47.

EXAMPLE 3 H 'i' NaCN A 300-ml. flask equipped with an ice-cooled condenser, gas inlet, nitrogen bubbler, and magnetic stirrer was assembled, flame-dried, and cooled to ambient temperature under nitrogen. Sodium azide (9.75 g., 0.15 mole, sieved through a 60 mesh screen) was added and the flask cooled in a solid carbon dioxide-acetone bath, while pure cyclopentene cc., 23.2 g., 0.34 mole) and cyanogen chloride ml., 48.8 g., 0.79 mole) were added. The mixture was allowed toreflux, with stirring, for 22 hours, during which time nitrogen was liberated. The excess cyanogen chloride was then removed by heating at C. for one hour. The resulting slurry was cooled to 10 C., diluted with dry ether (50 ml., 35.5 g., 0.47 mole), and filtered under nitrogen. Removal of the solvent from the filtrate on a rotary evaporator at 1 mm./40 C. gave 15.85 g. (98% yield) of an almost colorless oil. Distillation of this oil in an acid-washed short path still gave pure l-N-cyanoiminocyclopentane (15.2 g., 94% yield; n 1.4944). The melting point of the main fractions ranged from 20.5'to 21 C., as determined by differential thermal analysis. Mass spectrographic and infrared analysis of the product were in good agreement with the structure l-N- cyanoiminocyclopentane. Elemental analysisand molecular weight determinations on a sample obtained from a duplicate experiment were as follows:

A nalysis.Calcd. for CeHgNz: C, 66.64; H, 7.45; N, 25.91. Found: C, 67.09; H, 7.76; N, 25.62.

M01. wt. calcd. for C H N M.W., 108.15. Found: M.W., 99, 98 (freezing point in benzene).

Hydrolysis of the l-Ncyanoiminocyclopentane yielded cyclopentanone, cyanamide, and urea, as illustrated below.

l-N-cyanoiminocyclopentane, prepared as in Example 3 (5.40 g.,. 0.05 mole), and ether (10 ml., 7.1 g.) were added to distilled water (25 ml., 25 g.), acidified with 10% sulfuric acid (6 drops), and the mixture was heated with stirring at 45-49 C. for five hours. After standing at room temperature for 16 hours, the temperature of the reaction mixture was raised to 54 to 59 C., where it was held for 3% hours. The solution was then cooled to ambient temperature and evaporated to dryness on a rotary evaporator at 0.3 nun/40 C. There remained a white solid A (2.35 g.) and a volatile portion B. Extraction of A with ether and evaporation of the extract to dryness separated pure crystalline cyanamide (1.65 g., yield 78.6%) which was identified by comparison of its infrared spectrum with a known sample and by infrared and elemental analysis of the silver salt. Analysis Calcd. for Ag NCN: N, 10.95. Found: N, 11.36, 11.44.

'Ihe ether-insoluble fraction A (0.65 g., yield 21.6%) was chiefly urea (mp. 130133.5 C.). After one re- CH2 CH2 6 crystallization from acetone there was obtained 0.55 g. of urea melting at 131l33.5 C. A second recrystallization from absolute ethyl alcohol and ether gave pure urea (0.40 g., mp. 135136 C., yield 13.3%) which was identical in melting and mixed melting point with an authentic sample.

Extracting the volatile fraction B with ether in a continuous extractor followed by drying the extract over ma gnesium sulfate, filtering, and removing the solvent from the filtrate on an efficient column gave cyclopentanone (3.1 g., yield 74%) which was identified by infrared analysis, and by a 2,4-dinitrophenylhydrazone derivative (m.p. 145.6-146.2 C.). A mixed melting point of this derivative with the 2,4-dinitrophenylhydrazone prepared from an authentic sample of cyclopentanone was not depressed (mixed melting point 145.6146.4 C.).

To a flask equipped with a condenser, dropping funnel, magnetic stirrer, and thermometer was added silver nitrate (17.0 g., 0.1 mole) and distilled water (50 ml., 5 g., 2.8 moles). When solution was complete, l-N- cyanoiminocyclopentane, prepared as described above (5.41 g., 0.05 mole), was added over a period of five minutes. A mild exothermic reaction occurred and a small amount of yellow precipitate formed. Ether (5 ml., 3.6 g.) was added and the mixture heated at 40-50 C. for 20 minutes, and then cooled to ambient temperature; Addition of ammonium hydroxide (20 ml., 14% =2.8 g. NH OH+ 17.42 g. H O) caused additional yelow precipitate to form. The solid product was separated by filtration, washed on the filter with distilled water, and dried over P 0 at 0.1 mm./6070 C. (weight 12.70 g., yield 99.3%). The infrared spectra of this compound was idenical with that of a known sample of silver cyanamide.

Analysis.-'Calcd. for Ag CN Ag, 84.35; C, 4.69; N, 10.95. Found: Ag, 83.03; N, 11.03.

The filtrate was extracted with ether in a continuous extractor for 20 hours, the ether layer dried over anhydrous magnesium sulfate, filtered, and the ether removed by distillation. There remained 4.0 g. yield) of product containing cyclopentanone, identified by infrared analysis. Distillation of the crude product gave 3.73 g. (89% yield) of material having an n of 1.4353 and whose infrared spectrum was identical with that of authentic cyclopentanone.

CH3 CH3 I ON To a solution of cyanogen azide prepared as described in Example 5 from activated sodium azide (19.50 g., 0.3 mole) and cyanogen chloride (67 g., 1.1 mole) in acetonitrile ml., 93.5 g., 2.28 mole) was added 3,3-dimethyl-l-butene (57 g., 0.68 mole). The mixture was heated at 3443 C. for 15 hours, during which time ca. 0.3 mole of nitrogen was liberated. Continued heating at this temperature for 1% additional hours caused no further nitrogen evolution. After cooling to room temperature the mixture was diluted with ether, filtered, and the solvent and excess olefin removed in a rotary evaporator at 0.3 mm. and room temperature. There remained 35.61 g. (95.5% yield) of a light tan mobile oil. Distillation of this oil through a molecular type still at 0.3 mm. gave 29.58 g. (79.4% yield) of mixture of isomers consisting of ca. 74% 2,2-dimethyl-3-N-cyanoiminobutane and 26% 2-tertiary butyl-l-N-cyanoaziridine. Fractionation of 22.78 g. of this material through a 17 in. x 8 mm. spinning band column separated pure 2,2-dimethyl-3-N-cyanoiminobutane. Infrared and N-M-R analysis of the lower boiling fractions indicated that it contained major amounts of 2-tertiary butyl-l-cyanoaziridine.

EXAMPLE CH3 CH5 H:CC CCH3 NaCN CHa HaC CH3 H3CCCCH3 CC CH3 NCN HaC N CHa l ON A 500-ml. flask equipped with an ice-cooled condenser, magnetic stirrer, dropping funnel, nitrogen bubbler, and gas-inlet tube was assembled, flame-dried, and cooled to ambient temperature under nitrogen. Sodium azide (32.5 g., 0.5 mole) and dry acetonitrile (200 ml., 156.6 g.) were added and the flask cooled in an ice-salt bath. Cyanogen chloride (80 ml., 97.4 g., 1.58 mole) was distilled into the reaction mixture over a period of 1% hours at such a rate as to maintain the temperature between 418 C. When addition was complete, the reaction mixture was warmed to 25 C. and 2,3-dimethyl-2- butene (88.25 g., 1.05 mole) was added rapidly through the dropping funnel. During a reaction period of 14 hours at 3038 C., ca. 0.5 mole of nitrogen evolved. Heating at this temperature was continued for an additional two hours. The mixture was cooled to room temperature, diluted with ether (100 ml., 71.4 g.), filtered, and the solvent removed from the filtrate on a rotary evaporator at 0.3 mm. and room temperature. There remained 60.65 g. (98% yield) of a mixture of isomeric products. Distillation of the total product through a molecular type still at 0.1 mm. and a bath temperature of 3247 C. gave a colorless oil (60.34 g., 97.2% yield) consisting of ca. 92% 2,2-dimethyl-3-N-cyanoiminobutane and 8% 1-cyano-2,2,3,3-tetramethylaziridine as determined by N-M-R spectra. Fractionation of a 31.7 g. aliquot of this oil through a 17 in. x 8 mm. spinning band column separated pure 2,2-dimethyl-3-N-cyanoiminobutane (b.p. 38-40 C./0.05 mm.; 11 1.4570).

Analysis.Calcd. for C7H12N2: C, 67.69; H, 9.74; N, 22.56. Found: C, 68.07; H, 9.85; N, 23.02.

A slightly lower boiling fraction (b.p. 36 C./0.03 mm.; 1.4561) consisted predominantly of l-cyano- 2,2,3,3-tetramethylaziridine.

Analysis.Calcd. for C H N C, 67.69; H, 9.74; N, 22.56. Found: C, 67.92; H, 9.73; N, 22.61.

2,2-dimethyl-3-N-cyanoiminobutane was identified by infrared and N-M-R spectra and by hydrolysis to pinaco- O lone and cyanamide. 1-cyano-2,2,3,3-tetramethylaziridine was identified by its characteristic unsplit resonance at 83 cps. relative to tetramethylsilane.

EXAMPLE 6 H2C=CH2 NaCN H2O CH2 l CN of 30-35 C./0.2 mm. to give about 2 g. (15%) of l-cyanoaziridine, a colorless oil.

Analysis.Calcd. for C H N C, 52.9; H, 5.9; N, 41.2. Found: C, 51.8; H, 5.9; N, 41.3.

Infrared analysis of this product showed strong absorption at 4.50;. (CEN) and 6.80 1, 6.90; (CH with 8 no absorption at 6.0-6.2 1. characteristic of the C=N- group, and none at 7.2-7.4 (CH The N-M-R spectrum shows only one absortpion at 1:7.53.

EXAMPLE 7 A mixture of 3.25 g. (0.05 mole) of sodium azide and 20.3 g. (26 ml.) of acetonitrile was placed in an 80 ml. nickel-molybdenum-iron alloy-lined tube. The tube was cooled, and 6 g. (0.10 mole) of cyanogen chloride and 6 g. (0.14 mole) of propylene were added. The reactor was sealed and the charge held at 35 C. for 16 hours, during which time the pressure rose from 8-0 to 290 p.s.i. At this point, 7.7 g. (0.11 'mole) of cyclopentene was added to decompose any residual cyanogen azide. However, over a period of four hours there was no pressure rise so the product was removed from the reactor, filtered to remove sodium chloride, and evaporated on a rotating evaporator to remove low boiling material. On distillation through a short path still, 0.80 g. (19%) of Z-N-cyanoiminopropane, distilling at a pot temperature of 3046 C. with a pressure of 0.1-0.5 mm., n 1.4480, was obtained.

Analysis.Calcd. for C.,H N C, 58.5; H, 7.4; N, 34.1. Found: C, 59.1, 58.9, 58.6; H, 7.6, 7.6; N, 34.0, 34.2.

The infrared absorption spectrum showed strong absorption at 4.50;]. and 6.11 1. characteristic of CEN and C=N groups. The N-M-R spectrum had peaks at -r=7.59, 7.72.

EXAMPLE 8 Each of two 80 ml. nickel-molybdenum-iron alloy-lined pressure tubes was charged with 6.5 g. (0.10 mole) of sodium azide and 20.3 g. (26 ml.) of acetonitrile. The tubes were cooled and to one was added 12 g. (0.20 mole) of cyanogen chloride and 13 g. (0.31 mole) of propylene. The other was charged with 13 g. (0.21 mole) of cyanogen chloride and 12 g. (0.30 mole) propylene. The sealed tubes were then shaken at 35-37 C. for 18 hours. The contents were then combined and filtered to remove sodium chloride. The filtrate was evaporated on a rotating evaporator and the residual oil was distilled on a molecular-type still to give 9.26 g. (57%) of 2-N-cyanoiminopropane (11 1.4478-1.4488) and 30% of polymeric residue.

NCN

Two 80 ml. nickel-molybdenum-iron alloy-lined pressure vessels were charged with 6.5 g. (0.1 mole) of sodium azide and 20.3 g. (26 ml.) of acetonitrile, and to each was added 12 g. (0.20 mole) of cyanogen chloride and 16 g. (0.29 mole) of isobutylene. After the tubes were shaken for 20 hours at -36 C., the contents were removed, combined, filtered to remove the salt, and the filtrate was evaporated to remove volatile material. Distillation through a molecular-type still gave 50% yield of a mixture of 2,2-dimethyl-l-cyanoaziridine and 2-N-cyanoiminobutane, boiling at a pot temperature of 50 C./ 0.25 mm.

AnaIysis.-Calcd. for C H N C, 62.5; H, 8.4; N, 30.1. Found: C, 62.3, 62.1; H, 8.1, 8.2; N, 29.8.

In a similar experiment carried out at 2627 C., an 82% yield of the C H N mixture was obtained, which was shown by N-M-R to be 41% 2,2-dimethyl-1-cyanoaziridine and 59% 2-N-cyanoiminobutane.

If the above reaction isrepeated using benzene as the medium, the mixture consists of 77% 2-N-cyanoiminobutame and 23%'2,2-dimethy1rl-cyanoaziridine. With ethyl acetate as the medium, the mixture consists of 54% 2-N- cyanoiminobutane and 46% 2,2-dirnethyl 1 cyanoaziridine. 3 a t --In a duplication of the first of the above experiments, the isomer mixture was distilled through a 24 in. X 8 mm. :spinningband column and an essentially pure sample of 2,2-dimethyl-l-cyanoaziridine was obtained, b.p. 2425 C./-0.4 mm; n 1.4422. f

Analysis.CalCd. for C H N C, 62.5 H, 8.4. Found: 'C, 62:7;H, 8.2." The N-'M-R spectrum showed a sharp singlet at 1:857 for the methyl groups and a singlet at 1-=7.66 for the methylene protons.

From this same distillation was obtained essentially pure 2-N-'cyanoiminobutane, b.p. 30 C./0.4 mm.; n 1.4517.

The N-M-R of the 2-N-cyanoiminobutane shows absorption at 1:872, 8.83, 8.96, and 7.20, 7.32, 7.43 (7.56) for the ethyl group and -r=7.58 and 7.71 for the stereo isomeric syn-cyanomethyl group and anti-cyanomcthyl group, respectively.

EXAMPLE 10 ;Two 80 ml. nickel-molybdenum-iron alloy-lined pressure tubes were each charged with 6.5 g. (0.10 mole) of sodium azide and 20.3 g. (26 ml.) of acetonitrile, cooled' and to eachwas added 12 g. (0.20 mole) of cyanogen chloride and 16 g. (0.29 mole) of l-butene. The tubes were heated at 28- 36 C. for 18 hours, and after the resulting products were combined, they were filtered to remove sodium chloride, and the filtrate evaporated to remove solvent and unreactcd starting material. Distillation on a molecular-type still afforded 3 g. of 2-N- cyanoiminobutane;n 1.4532. 1 ;,.Analysis.-Calcd. for. C H N C, 62.5; H, 8.4; N, 30.1.. Found: C, 62.7, 62.4; H, 8.6, 8.4; N, 29.3.

The N-M-R spectrum showed this to be a pure material.

NON

To a cooled mixture of 40.6 g. (52 ml.) of acetonitrile and 13.0 g. (0.20 mole) of sodium azide in a 240 ml. nickel-molybdenum-iron alloy-lined pressure reactor tube was added 24 g. (0.40 mole) of cyanogen chloride and 32 g. (0.57 mole) of l-butene. The mixture was shaken for 16 hours at 27-35 C., filtered to remove sodium chloride, and evaporated on a rotating evaporator to remove l-buterie, cyanogen chloride, and solvent. The residue consisted of 16.5 g. (86%) of essentially pure Z-N-cyanoiminobutane, which was distilled through a short path still to 'give'9.6 g. (50%) of the pure 2-N-cyanoiminobutane along with quite a large amount of polymer.

EXAMPLE 12 aC-CH=CHCH3 NaCN HgQ-CHrO-CH;

' I i t. 4 :r 7 i. I): fflInto each of two cooled 80 m1, nickel-molybdenumiron alloy-lined pressure vessels, charged with 6.5 g. (0.10 mole) of sodium azide and 20.3 g. (26- ml.)of acetonitrile, was distilled 12 g. (0.20 mole) of cyanogen chloride and 16 g. (0.29 mole) of cis-2-butene. These mixtures were heated at 3236 C. for 18 hours, combined, filtered to remove, sodium chloride, and the filtrate was evaporated on a rotary evaporator to remove the volatiles, leaving 16.5 g. (86%) of crude 2-N-cyanoiminobutane. On distillation at a'pot temperature of 3541 C. and 0.25-0.15 mm, 1301 g. 68%) of the pure Z-N-cyanoiminobutane, n 114528 14538, was obtained.

10 Analysis.Calcd. for C H N C, 62.5; H, 8.4; N, 30.1. Found: C, 62.3, 62.5; H, 8.5, 8.5; N, 29.8, 30.0.

Proton magnetic resonance showed the crude material to be almost pure Z-N-cyanoiminobutane.

Cyanogen chloride (12 g., 0.20 mole) and transibutene (16 g., 0.29 mole) were consecutively added to a cooled ml. nickel-molybdenum-iron alloy-lined pressure vessel containing 6.5 g. (0.10 mole) of sodium azide and 19.5 g. (25 ml.) of acetonitrile. After shaking for 19 hours at 24-28 C., the contents were removed, filtered to remove the sodium chloride, and the filtrate evaporated under reduced pressure to remove unreactcd reactants and solvent. The crude residue (7.45 g., 78%) was shown by N-M-R to be nearly pure 2-N-cyanoimin0 butane. On distillation at a pot temperature of 2752 C. and 0.35-0.45 mm., 4.34 g. (45%) of pure Z-N-cyanoiminobutane, 111 1.45301.4540, was obtained.

Analysis.--Calcd. for C H N C, 62.5 H, 8.4; N, 30.1. Found: C, 62.5, 62.5; H, 8.5, 8.4; N, 30.1.

A mixture of 3.25 g. (0.05 mole) of sodium azide and 20 ml. (24 g., 0.40 mole) of cyanogen chloride was stirred for three hours in a 50 ml. flask fitted with a condenser, dropping funnel, and thermometer and connected to a wet test meter and 10 ml. (6.7 g., 0.097 mole) of 2- methyl-Z-butene was added. After 16.5 hours at 20 C., 915 ml. (73%) of nitrogen was evolved. An additional 5 ml. (3.3 g., 0.047 mole) of 2-methyl-2-butene was added along with 10 ml. (7.8 g.) of acetonitrile, and the reaction mixture was heated at 3048 C. for 4.7 hours, during which time another 250 ml. (20%) of nitrogen was evolved. The reaction mixture was then cooled, filtered to remove sodium chloride, and the filtrate was evaporated to remove cyanogen chloride, olefin, and acetonitrile. The residual oil was distilled through a short path still to give 3.6 g. (66%) of 2-methyl-3-N-cyanoiminobutane boiling at a pot temperature of 40-50" C.'/ 0.1 mm.; n 1.4521-1.4528.

.Analysis.-Calcd. for C H N C, 65.5; H, 9.2; N, 25.4. Found: C, 65.4; H, 9.2; N, 25.6.

. In a duplication of the above experiment, the N-M-R spectrum of the product was shown to consist of peaks at 7:758, 7.78 for the synand anti-cyanomethyl groups, a doublet at' 8.79 and 8.88 for the isopropyl methyls and a seven line pattern from 7:6.85-7-53 for the isopropyl -CH.

EXAMPLE 15 I 1 time A mixture of 3.25 g. (0.05 mole) of sodium azide, 24 g. (20 ml., 0.38 mole) of cyanogen chloride, and 13.4 g. (20 ml., 0.16 mole) of l-hexene was stirred at room temperature for 22 hours, then at 3148 for /2 hour, during which time 815 ml. (63%) of nitrogen was evolved. The mixture was filtered to remove sodium chloride, and the filtrate was concentrated using a rotating evaporator. Distillation of the oily residue gave 2.35 g. (38%) of 2-N-cyanoiminohexane, 11 1.45671.4570, boiling at a pot temperature of 4147 C./ 0.07 mm.

Analysis.Calcd. for C H N C, 67.8; H, 9.8; N, 22.6. Found: C, 67.6; H, 9.4; N, 23.2, 23.4.

The structure of the 2-N-cyanoiminohexane was proved by treatment with aqueous silver nitrate-solution which gave a'yellow precipitate, shown to be silver cyanamide, and a water solution from which 2-hexanone was ex- 11 tracted with ether. The identity of the ketone was shown by its conversion to the semicarbazide derivative, m.p. 121l22 C. (reported 121 C. in Shriner and Fuson, Identification of Organic Compounds)- Each of two 80 ml. nickel-molybdenum-iron alloy-lined tubes was charged with 6.5 g. (0.1 mole) of sodium azide and 20.3 g. (26 ml.) of acetonitrile, cooled, and to each was added 12 g. (0.20 mole) of cyanogen chloride and 20 g. (0.29 mole) of 3-methyl-1-butene. The sealed tubes were heated at 23-40" C. for 19 hours, after which the combined products were filtered to remove sodium chloride. The filtrate was concentrated on a rotating evaporator and distillation through a 24 in. x 8 mm. spinning band column gave a 41% yield of a crude mixture of 3- methyl 2 c yanoiminobutane and 2-isopropyl-1-cyanoaziridine, along with 36% of polymeric residue.

The first fraction from the distillation had a boiling point of 38-39 C./0.35 mm. and was shown by N-M-R to be about 90% 2-isopropyl-l-cyanoaziridine, while higher boiling fractions, b.p. 42 C./0.40 mm., were shown to be nearly pure 3-methyl-2-N-cyanoiminobutane.

In a similar experiment at 2627 C., an 86% yield of the isomer mixture was obtained.

EXAMPLE 17 To 41 milliliters of acetonitrile solution containing 6.8 g. (0.10 mole) of cyanogen azide was added 33 g. (.50 mole) of cyclopentadiene. This solution was held at C. for 7.4 hours, during which time 2.05 liters (81.5%) of nitrogen was evolved, excess cyanogen azide, and excess cyclopentadiene were removed on a rotating evaporator at 1 mm. pressure. Distillation at 1,14, using a mercury vapor pump, afforded 5.87 g. (55%) of Z-cyanoiminocyclopentene-l, b.p. 3642 C., 1 pressure; 21 1.5648.

Analysis.Calcd. for C H N C, 67.9; H, 5.7. Found: C, 68.1, 69,5; H, 5.8, 6.0.

The infrared spectrum showed absorption at 4.55;, 6.25;:., and 637p. attributable, respectively, to the cyano group, and C=N and C=C groups, and in the fingerprint region the spectrum was quite similar to cyclopentenone.

EXAMPLE 18 An acetonitrile solution (29 ml.) containing 6.8 g. (0.1 mole) of cyanogen azide was added to g. (0.21 mole) of methylenecyclohexane (shown to be pure by gas chromatography). Nitrogen was liberated readily and over a period of 9 hours 1.99 l. of nitrogen (80%) was obtained, with a reaction temperature of 2228 C. After removal of solvent and excess methylenecyclohexane on a rotating evaporator, 11.75 g. of crude product (87%) was obtained. Distillation at a pot temperature of 96-103 C./l mm. gave 8.30 g. (61%) of a mixture of l-cyanoiminocycloheptane and l-cyano-Z-cyclopentamethyleneaziridine; 21 1.4880 to 1.5026.

Analysis.Calcd. for C H N C, 70.5; H, 8.9; N, 20.6. Found: C, 70.5, 70.5; H, 8.7, 8.9; N, 20.2, 20.4.

Proton magnetic resonance analysis indicated that the mixture contained 71% of the cyanoiminocycloheptane and'29% of the aziridine. This ratio changes with change of reaction medium, e.'g., in ethyl acetate solution, 61% l-cyanoiminocycloheptane and 39% of aziridine are formed while in benzene solution, 82% of cyanoiminocycloheptane and 18% of aziridine are produced.

The above process was repeated using 5 g. (0.05 mole) of methylenecyclohexane, 25 ml. of dimethylformamide, and 1.7 g. (0.025 mole) of cyanogen azide. After 16 hours at 25 C. there was obtained 2 g. of an oil which was shown by N-M-R spectroscopy to be pure l-cyano-v iminocycloheptane containing no 1-cyano-2-cyclopentamethyleneaziridine. I

The above process was again repeated using 5 g. of methylenecyclohexane dissolved in 10 ml. of acetic acid and a small amount of 2.5 molar cyanogen azide in ethyl acetate at 40 C. After evaporation of the solvents: and excess reactants, an oil was obtained -whose ;N,-M-R spectrum indicated that it was %y1-cyano-2-cyclo pentamethyleneaziridine containing no l-cyanoiminocycloheptane. 1

EXAMPLE 19 A solution of 6.8 g. (0.10 mole) of cyanogen azide in 28 ml. of acetonitrile was added to 0.5 g. (0.14 mole) of methylenecyclobutane at room temperature purified by preparative gas chromatography. Reaction was immediate and over a 63-hour period, 1.89 l. (75%) of nitrogen was evolved. After evaporation of solvent, 7.67 g. (79%) of crude adduct was obtained, which upon distillation through a short path still at a pot temperature of 55- 63.5 C./0.05-0.25 mm. gave 5.10 g. (52%) of 1-cyano iminocyclopentane; n 1.4928l.4937."

Analysis.Calcd. for C H N C, 66.6; H, 7.5; N, 25.9. Found: C, 64.4, 64.0; H, 7.3, 7.4; N, 26.5, 26.5.

The nuclear magnetic resonance spectrum of this material was identical in all respects with the spectrumof the cyanoiminocyclopentane produced by the reaction of cyanogen azide with cyclopentene. 1 I

Forty milliliters of acetonitrile solution containing 10.2 g. (0.15 mole) of cyanogen azide was added to 24 g. (0.25 mole) of "-l-methylcyclohexene', and over a 23.5 hour period 2.48 1. (66%) of nitrogen was evolved. After evaporation of the solvent, the crude product was in-' vestigated by N-M-R spectroscopy and three compounds were identified as constituents: -1-cyanoimino-2 Incthylcyclohexane, 45%; 1 (1 N-cyanoiminoethyl')-cyclopentane, 25%; and 1-cyano-2-methyl-2,3-cyclohexanyl aziridine, 17%. Distillation of the mixture through a short path still at a pot temperature of 39-77 C'./0.05-0.'-10 mm. gave 7.23 g. (35%) of the isomer mixture.

Analysis-Calm. for C H N C, 70.6; H,- 8i9;-N', 20.6. Found: C, 70.3, 70.2; H, 9.7, 9.6. i

13 EXAMPLE 21 I I. --"%NCN The reaction of cyanogen azide with methylenecyclobutane containing 6% l-methylcyclobutene at room temperature gave predominantly l-cyanoiminocyclopentane; however, N M-R spectroscopy Strongly indicates that a small amount of 1-cyano 2-methyl-2,3-cyclobutanylaziridine is present in the isomeric C H N mixture. 1

EXAMPLE 22 CN I11 NCN NQCN CICHQCH==CH ClCHzCHCI-I 01cm CH1 \A solution of 1.9 g. (2.8 mmoles) of cyanogen azide in 1 ml. of carbon tetrachloride was added to 0.11 g. (1.4 mmole) of allyl chloride, and the mixture was allowed to stand for 2 hours at ambient temperature. The magnetic resonance spectra of the resulting solution was determined using a Varian high resolution N-M-R spectrometer and electromagnet as a frequency of 30 mc. and a field of 7500 gauss. The N-M-R spectrum indicated the presence of both 1-cyano-2-chloromethylaziridine and 2- cyanoimino-3-chloropropane.

EXAMPLE 23 o NCN y N3CN y CH3 oH=orn CH3 com Following the procedure of Example 22, cyanogen azide and 0.10 g. (1.4 mmole) of methyl vinyl ketone were reacted with liberation of nitrogen. The N-M-R spectrum of the product indicated the presence of 2-cyanoiminopropanone-3.

EXAMPLE 24 (IN N Allyl alcohol (0.08 g., 1.4 mmole) was treated with cyanogen azide according to the procedure of Example 22. The N-M-R spectrum of the resulting solution indicated the presence of 1-cyano-2-hydroxymethylaziridine in the reaction product.

EXAMPLE 25 CN I l NCN N CN (onnisicrhcm (CHi)3SiCH-CH, cnnasiii-cn,

Trimethylvinyl silane (0.1 g., l mmole) was added to cyanogen azidefin carbon tetrachloride according to. the procedure of Example 22. The N-M-R spectrum of the product mixture indicated that both l-trimethylsilyl-lcyanoirninoethane and 1 cyano-Z-trimethylsilylaziridine were present in the product mixture.

EXAMPLE 26 N CN onmc-s-orhcm (CHahS CHCH: onmsocrn A cyanogen azide solution containing 0.19 g. (2.81 mmole) in 1 ml. of carbon tetrachloride was added to 0.1 g. (1 mmole) of tertiary butyl vinyl sulfide according to the procedure of Example 22. The N-M-R spectrum of the product indicated presence of both l-cyanoimino-ltertiary butylthioethane and I-cyano-Z-tertiary butyl thioaziridine.

Cyanogen azide was prepared by stirring sodium azide (6.5 g., 0.1 mole) and cyanogen chloride (50 ml.)-at reflux temperatures for 20 hours. To this mixture was added ethyl vinylether (8.2 g., 0.11 mole) dissolved in diethyl ether (20 ml.) overaperiod of 15 minutes, while maintaining the reaction temperature "at1 6-18" C. The

reaction mixture was stirred at this temperature for a Analysis.Calcd. for C H N O: C, 53.55; H, 7.19; N, 24.98. Found: C, 50.52; H, 7.48; N, 24.60, 24.66, 24.82.

The infrared analysis showed strong absorption at 3.35, 3.45; (C-H), 4.45 (C=N), 6.15; (C=N), and in the 8 region (C-O). These data indicate that the product consists principally of l-ethoxy-l-N-cyanoiminoethane, 1.e.,

When other reactants are substituted for the ethyl vinyl ether of Example 27 there are obtained other cyanoimines coming within the scope of the invention. For example substitution of methyl vinyl ether results in l-methoxy-l- N-cyanoiminoethane. Substitution of 1-chloro-2-methoxyethylene and 1,2-diethoxyethylene results in, respectively, 1-methoxy-1-N-eyanoimino-Z-chloroethane and 1,2-diethoxy-l-N-cyanoiminoethane.

The reaction of cyanogen azide with ethylenic compounds can be used as an analytical means for determining the approximate extent of ethylenic unsaturationin an unknown composition by measuring the amount of nitrogen liberated.

This invention also provides a means for converting ethylenically unsaturated compounds to useful carbonyl compounds. As shown by Example 3, for instance, the reaction product of cyclopentene with cyanogen azide is readily converted to cyclopentanone by simple hydrolysis. Cyclopentanone is a polymer solvent, and it can be converted by oxidation with nitric acid to glutaric acid, which can be reacted with amines and glycols, respectively, to form useful polyamides and polyesters. As is further shown in Example 3, cyanamide is another product of the hydrolysis. Cyanamide is a valuable intermediate, e.g., for preparing resins of the amide-formaldehyde type.

The products obtained from monomeric ethylenically unsaturated compounds are useful as adhesives for bonding neoprene to itself, to natural rubber, and to other substrates. For example, when a small sample of the l-cyanQF-i iminocyclopentene-Z of Example 17 was spread between two /8" neoprene sheets and the sheets pressed together at 130 C. and 2000 p.s.i. for 5 minutes, a strong bond between the neoprene sheets was formed. Similarly, /8" thick strips of neoprene and natural rubber were firmly joined by pressing a small sample of 2,2-dimethyl-1-cyanoaziridine, prepared as in Example 9, between them and heating at C. and 4000 p.s.i. for 2 minutes.

Since obvious modifications and equivalents will be evident to those skilled in the chemical arts, I propose to be bound solely by the appended claims.

15 16 The embodiments of theinvention in which an exclusive 5. Bicyclo[2.2.l]heptane-2-N-cyanoimine. proper ty or privilege is claimed are defined asfollows: 6. 1-N-cyanoiminocyclopentane.

1. An N-cyanoimine of the formula 7. 2,2.-dirneth'yl-3 N-cyanoiminobutane.

/ R 8. Z-N-cyanoiminopropane.

R2-(IJ =N N, References Cited R; I Cheiriiical AbetractsQvolQ53, 1695 (g) wherein the Rs taken individually, contain up'to 18 car- 7 hens and are membcrs of the group consisting of hydro- E N H N Primary Examiner gen, alkOXY and dw i d j w a b G. A. SCHWARTZ-Assistant Examiner joined to form a divalent akylene group of 2-10 carbons. I

US. Cl. X.R. 3. 1,Z-diethoxy-1-N cyanoiminoethane. 260551 C i 4. l-N-cyanoiminocyclohexane. u 

1. AN N-CYANOIMINE OF THE FORMULA 